Hello boys and ghouls. This is my first guide on Mobafire, and I thought I should spend a bit of my knowledge on Vi, with which I've been playing since she came out on PBE.

Vi is a bruiser champion, excelling at solo top and jungle play (even at mid, I'd say, but then again, I play Zed mid, so it might be just my extravagance). She has strong AoE and wearing-down skills in her repertoire with decent durability.

This build presents a tanky bruiser Vi, whose job is to initiate fights, disorganize enemy team and ultimately wear them down.

I went with 9/21 masteries because I prefer tankyness over sheer damage output. Vi is extremely straight-forward champion and strong initiator, so it is desirable for you to be able to survive as long as possible. I'm certain that 21/9 masteries could work easily as well, but in that case I suggest you make sure you have at least one additional tanky champ in your team.

Runes are pretty standard: AD quint, flat armor seals, per lvl MR glyphs and armor penetration marks. Flat armor is very much needed early game, MR per lvl helps against those pesky late-game AP's, and AD quint and Armor penetration help with overall damage output.

Yes, I'm aware that this is an expensive build, but I find it quite satisfying as it can be built in parts without losing your overall effectiveness.

This item build gives you loads of health, armor and mr, while at same time providing decent capabilities for damage output.
Now, to describe why I take certain items:

Boots of speed: Vi needs mobility for running down the opponents and quickly making her way around the map, and slow reduction is amazing at keeping you at your optimal. You can easily replace them with Mercury boots if the enemy team is filled with more-than-usual cc's and ap's.

Trinity Force: Vi can use pretty much everything from this item. It can be replaced by Iceborn gauntlet if you are in need of CDR and you can't get blue buff or if you need more armor, but I wouldn't suggest it usually.

Black Cleaver: Well, everyone knows this item nowadays. Core item for any bruiser with self-respect.

Runic Bulwark: Loads of armor, hp, and most importantly mr, with aura? Yes,please. Pretty decent all-around item which helps Vi get her bulkiness.

Warmonger: Moar hp for her passive. Passive hp regen is also pretty decent combined with other hp items.

Atma's: Armor and ad. 'Nuff said.

Keep in mind that you can easily swap most of these items for other similar items if you think that situation demands it. But be careful with trade-offs.

I find Q a very decent dmg-output ability, even more with some CDR, and great initiating tool.
E is also very close to it, and both get their cd's lowered a lot per rank of ability, so choose carefully what you wish to lvl first.